Clasp with rotate disengagement

ABSTRACT

A clasp for holding two ends of cords or the like together includes a shaft member insertable into and engageable with a latch member. The latch member is a round tube having an open front end through which the shaft member may be inserted and withdrawn. Attached to the latch member is a spring member with a hook (tab) extending from a free end thereof through a hole in the side of the latch member. The shaft has a notch. The clasp is engaged by aligning the tab of the latch member with the notch of the shaft member and pushing the shaft member into the open end of the latch member until the tab engages the notch. The clasp is disengaged by rotating the shaft member relative to the latch member so that the tab is urged out of the notch, then pulling the shaft member out of the latch member.

TECHNICAL FIELD OF THE INVENTION

[0001] The invention is directed to clasps for jewelry and the like and, more particularly, to clasps of the type having an inner member which is inserted into and releasably retained within an outer member.

BACKGROUND OF THE INVENTION

[0002] Clasps are used for connecting the terminal ends of one or more flexible members to one another, such as necklaces, bracelets, watch bands, cords and the like. Clasps are also known for connecting an object, such as a fish hook to a line.

[0003] A type of clasp is known wherein an inner shaft member is formed having a tongue or hook disposed to engage a recess or opening in an outer latch member. These type clasps share a disadvantage in that it is relatively easy to depress the tongue, and thereby permit the shaft member to disengage from the latch member. Solutions to this problem have tended to create clasps which are complex, expensive to manufacture and difficult to use.

[0004] Other types of clasps have a U-shaped member that another member slips over to hold the open end of the U together. If these fasteners are required to be small, they are difficult to use.

[0005] Thus, there remains a continuing need for a clasp that can be made small yet is still easy for the user to use (engage and disengage), relatively inexpensive to manufacture, and less likely to disengage while in use.

[0006] Examples of clasps are disclosed in the following documents: U.S. Pat. Nos. 4,024,607; 4,246,679; 4,364,155; 4,426,854; 4,566,159; 4,571,788; 4,958,420; 5,457,860; 5,628,095; 6,058,576; and 6,088,884.

SUMMARY OF THE INVENTION

[0007] An object of the present invention is to provide a clasp that can be made small and substantially reduce the likelihood of unwanted disengagement.

[0008] Another object of this invention is to provide a clasp which can have varying amounts of holding power with a relatively minor design change.

[0009] Another object of this invention is to provide a clasp which is relatively simple in construction, easy and economical to manufacture and easy to use even with gloved hands.

[0010] This invention is a clasp for releasably holding two cord ends or the like together such as two ends of a necklace, or such as a fish hook to a line.

[0011] According to the invention, a shaft member is insertable into and engageable with a latch member. The latch member is in the form of a round tube (cylinder) with a hole in the side and an open front end through which the shaft member may be inserted and withdrawn. Attached to the exterior of the latch member is a spring member with a hook portion (“tab”) which extends through the hole to the interior of the latch member. The hole in the side of the latch member need only be large enough to permit the tab to go through, and it is disposed near the insertion (front) end of the latch member. The other (rear) end of the latch member is open, and has a ring to which one cord or one end of a necklace may be attached. Alternatively, the rear end of the latch member can be closed. Alternatively, the spring member can be formed integrally with the latch member.

[0012] The shaft member can be as simple as a rod with a notch in the side. The shaft member also has an eyelet to which a cord or other end of a necklace is attached.

[0013] The clasp is engaged by aligning the tab of the latch member with the notch of the shaft member and pushing the shaft member into the open end of the latch member such that the tab is engaged with the notch.

[0014] The clasp is disengaged by rotating the shaft member relative to the latch member so that the tab is pushed (urged) out of the notch, then, pulling the shaft member out of the latch member.

[0015] Other objects, features and advantages of the invention will become apparent in light of the following description thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Reference will be made in detail to preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. The drawings are intended to be illustrative, not limiting. Certain elements selected drawings may be illustrated not-to-scale, for illustrative clarity.

[0017] Often, similar elements throughout the drawings may be referred to by similar reference numerals. For example, the element 199 in a figure (or embodiment) may be similar in many respects to the element 299 in another figure (or embodiment). Such a relationship, if any, between similar elements in different figures or embodiments will become apparent throughout the specification, including, if applicable, in the claims and abstract. In some cases, similar elements may be referred to with similar numbers in a single drawing. For example, a plurality of elements 199 may be referred to as 199 a, 199 b, 199 c, etc.

[0018] The structure, operation, and advantages of the present preferred embodiment of the invention will become further apparent upon consideration of the following description taken in conjunction with the accompanying figures, wherein:

[0019]FIG. 1 is a side, cross-sectional view of an embodiment of a clasp, according to the invention;

[0020]FIGS. 1A and 1B are end cross-sectional views of the shaft member of the clasp of FIG. 1, taken along lines a-a and b-b through the shaft member, respectively, according to the invention;

[0021]FIG. 1C is an end cross-sectional view of the latch member of the clasp of FIG. 1, taken on a line c-c through the latch member, according to the invention;

[0022]FIG. 2 is a side, cross-sectional view of the clasp of FIG. 1, showing the shaft member partially inserted into the latch member, according to the invention;

[0023]FIG. 3 is a side, cross-sectional view of the clasp of FIG. 1, showing the shaft member fully inserted into the latch member, according to the invention;

[0024]FIG. 4A is an end cross-sectional view, taken on a line d-d through FIG. 2, according to the invention;

[0025]FIG. 4B is an end cross-sectional view, taken on a line e-e through FIG. 3, according to the invention;

[0026]FIG. 4C is an end cross-sectional view, comparable to the view of FIG. 4B, with the shaft member rotated, according to the invention;

[0027]FIG. 5 is a partial side, cross-sectional view of an alternate embodiment of a clasp, according to the invention;

[0028]FIG. 6 is a partial side, cross-sectional view of an alternate embodiment of a clasp, according to the invention;

[0029]FIG. 7 is a partial end, cross-sectional view of an alternate embodiment of a clasp, according to the invention; and

[0030]FIG. 8 is a side, cross-sectional view of an alternate embodiment of a latch member for a clasp, according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0031] The invention is a clasp for connecting the terminal ends of a flexible, typically elongate element (or elements), such as articles of jewelry, such as necklaces, bracelets, watch bands and the like. The invention is also applicable to connecting two dissimilar elements with one another for example, a fish hook to a fishing line.

[0032] An Embodiment of the Clasp

[0033]FIGS. 1, 1A, 1B, 1C, 2, 3, 4A, 4B and 4C illustrate a first embodiment of the clasp 100 of the present invention, the major components of which are:

[0034] a latch member 110;

[0035] a shaft member 130; and

[0036] a spring member 150.

[0037] The latch member 110 is elongate and is generally cylindrical (tubular), having a front end 112, a rear end 114 which is opposite the front end 112, an inside surface 116, and an outside surface 118. The latch member 110 is open at the front end 112, and is preferably open at the rear end 114. The latch member 110 has an inside diameter D1. The inside surface 116 is preferably of uniform diameter, rather than tapered. The outside surface 118 is shown as being of uniform diameter, but it need not be. The latch member 110 has a cylindrical wall 120. A hole (opening) 122 extends through the wall 120, from the outside surface 118 to the inside surface 116 thereof, at an intermediate position along the length of the latch member 110, such as approximately 25-50% of the distance from the front end 112 to the rear end 114. This hole 122 is for receiving a hook portion (“tab”) 154 of a spring member 150, described in greater detail hereinbelow. Another hole (opening) 124 extends through the wall 120 of the latch member 110, from the outside surface 118 to the inside surface 116 thereof, at a location closely adjacent the rear end 114 (e.g., within 10% of the length of the latch member 110), for receiving a ring 126 which is described in greater detail hereinbelow. The latch member 110 is suitably constructed as a thin-walled, strong, round tube, such as of metal (e.g., tin, steel, silver, gold, and alloys thereof).

[0038] The shaft member 130 is elongate and is generally cylindrical (tubular), having a front end 132, a rear end 134 which is opposite the front end 132, and an outside surface (external) 136. The shaft member 110 has an outside diameter D2, which is slightly (e.g., for a jewelry clasp, a few thousandths of an inch) less than the inside diameter D1 of the latch member 110. This is so the shaft member 130 can be inserted into the latch member 110. (The open rear end 114 of the latch member 110 allows for debris to be ejected from the latch member 110 when the shaft member 130 is inserted therein.) The shaft member 130 is suitably constructed of a solid, hard, round rod, such as of metal. (The rear end 134 of the shaft member 130 is shown simplified, in FIG. 1, for illustrative clarity.)

[0039] The front end 132 of the shaft member 130 is rounded. At an intermediate position along its length, such as approximately halfway between the front end 132 and the rear end 134, a notch (groove) 140 is provided which extends radially into the shaft member 130 a distance d2. The distance d2 is suitably a fraction, such as approximately one-third to one-half of the shaft diameter D2. The notch 140 has a longitudinal extent which corresponds to a thickness of a tab (154) of a spring member (150), which is described in greater detail hereinbelow. The notch 140 extends circumferentially, approximately 180-degrees (i.e., halfway) around the shaft member 130, has a front wall 142, a back wall 144, and a ramp (cam) surface 146.

[0040]FIGS. 1A and 1B are cross-sections of the shaft member 130, taken at various positions along its length—namely, referring to FIG. 1, at a position (a-a) forward of the notch 140, and at the location (b-b) through the notch 140, respectively. The front end 132 of the shaft member 130 is rounded. Rearward of the notch 140, the shaft member 130 is suitably substantially cylindrical. The overall diameter of the shaft member 130 diminishes from the notch 140 to the front end thereof. The shaft member 130 is tapered, from the front end 132 towards the rear end 134 so that it can easily be inserted into the latch member 110, as discussed hereinbelow.

[0041] The spring member 150 is elongate and is made of a resilient material, such as spring steel. It has two major portions: an elongate body portion 152 having two ends (not numbered in the figures)—a one end which is affixed to the latch member and an opposite end which is a free end. The spring member 150 has a tab (pawl, tooth) portion 154 extending from the free end (the free end) of the body portion 152. The tab 154 is preferably contiguous, and integrally formed with the body portion 152. The spring member 150 is secured (affixed) to the external surface 118 of the latch member 110 in any suitably manner, such as with a rivet 156 (alternatively, with a bolt, a screw, a tab, welded, soldered, glue, or the like).

[0042] The tab 154 extends at a right angle from the free end of the body portion 152, through the hole 122, into the interior (bore) of the latch member 110, a distance d1, which is preferably less than half, preferably one-quarter of, the inside diameter D1 of the latch member 110, and which is slightly less than the depth d2 of the notch 140. Stated in other terms, the depth d2 of the notch 140 is slightly greater than the length d1 of the tab 154. Since the body portion 152 is a resilient material, the tab 154 can deflect resiliently, radially out of the hole 122 in the latch member 110 when the shaft member 130 is inserted therein, as discussed hereinbelow. The tab 154 itself need not be resilient and, although shown as being integral with the body portion 152, it can be a separate element which is assembled to the end of the body portion 152. The tab 154 has a width (best viewed in FIG. 1C), which is approximately one-quarter (shown not-to-scale, for illustrative clarity) of the inside diameter D1 of the latch member 110. FIG. 1C is a cross-sectional view taken on a line c-c through the latch member 110 of FIG. 1, and shows the tab 154 of the spring member 150 extending through the wall 120, into the bore (interior) of the latch member 110.

[0043]FIG. 2 illustrates the clasp 100, with the shaft member 130 partially inserted into the latch member 110. A ring 126 is disposed through the hole 124, and is for attaching to an end 103 of an elongate element 102, such as a jewelry chain. (The ring 126 and elongate element 102 are omitted from FIGS. 1 and 3, for illustrative clarity.) In this view, it is shown that the rear end 134 of the shaft member 130 may be formed with an area of reduced diameter having a hole (eyelet) 146 therethrough for receiving a ring 127 which is for attaching to an end 105 of an elongate element 104, such as a jewelry chain. (The ring 127 and elongate element 104 are omitted from FIGS. 1 and 3, for illustrative clarity.) The two ends 103 and 105 of elongate elements 102 and 104, respectively, can be two opposite ends of a single element, such as a jewelry chain.

[0044]FIG. 3 illustrates the clasp 100, with the shaft member 130 fully inserted into the latch member 110.

[0045] Use of the Clasp

[0046] The sequence of operations to engage the clasp 100 is to first align the notch 140 with the tab 154, both of which are shown as being in the “12 O'clock” position in FIGS. 1, 1A, 1B, 1C, 2 and 3. Then, the user inserts the front end 132 of the shaft member 130 into the front end 112 of the latch member 110. This causes the tab 154 of the spring member 150 to deflect resiliently upwards. FIGS. 2 and 4A illustrate the shaft member 130 partially inserted into the latch member 110, and the tab 154 having been resiliently deflected upwards, so that it is out of the bore of the latch member. The user continues to insert the shaft member 130 into the latch member 110, and when the notch 140 aligns under the tab 154, the tab 154 will enter the notch 140, thereby resisting (substantially preventing) further insertion of the shaft member 130 into the latch member 110 or removal of the shaft member 130 from the latch member 110. FIGS. 3 and 4B illustrate the shaft member 130 fully inserted into the latch member 110, and the tab 154 disposed within the notch 140.

[0047] The sequence of operations to disengage the clasp is illustrated primarily by FIG. 4C. First, the user rotates the shaft member 130, for example to the “7 O'clock” position. This will cause the tab 154 to “ride up” along the ramp (cam) surface 146 of the notch 140 until it is at the external surface 136 of the shaft member 130 (i.e., until it is no longer in the notch 140). (Rotating the shaft member 130 urges the tab 154 out of the notch 140.) The shaft member 130 can then simply be withdrawn from the latch member 110 (in the reverse direction from engagement). In other words, rotation of the shaft member 130 forces the tab 154 of the spring member 150 out of the bore of the latch member 110.

[0048] An advantage of the present invention is that the clasp is relatively immune from accidental disengagement. It is difficult to cause the tab to exit the notch other than by rotating the shaft element, and the force of the tab against the ramped surface is sufficient to require advertent action to be taken to disengage the clasp. The disengagement force flexes the spring element, and is directed opposite to the tension expected in normal use. Catching the spring element and exerting a force to flex the spring element is very difficult to accomplish, other than by rotating the shaft element. A force in any other direction will not disengage the shaft member. Even pushing directly on the tab will not disengage the clasp. A rotation pressure such as used in disengagement of insufficient strength will not disengage the clasp.

[0049] Alternate Embodiments

[0050] The resilient force with which the tab 154 is maintained within the bore of the latch member 110 can be designed by changing the dimensions (e.g., length) or the material (namely, with regard to spring constant) of the spring member 150, or by changing the location of the rivet 156. Also, by modifying the radial extent of the tab 154 and, as described hereinbelow, its angle, the force necessary to disengage the shaft member 130 from the latch member 110 can be altered.

[0051] The shaft member 130 should have an overall length which is sufficient (long enough) to allow the tab 154 to enter the notch 140, but which is short enough to keep the overall clasp 100 of small size for jewelry items. It is within the scope of the invention that multiple notches can be provided in the shaft member to permit engagement of the tab 154 at different engagement distances, to permit adjusting the overall, ends-connected length of a cord 102 or the like. It is also within the scope of the invention that multiple tabs can be provided along the length of the spring element, extending though corresponding multiple holes in the latch member, to engage corresponding multiple notches on the shaft member, to increase the holding power of the clasp.

[0052] The angle between the tab 154 and the body portion 152 of the spring member 150 is illustrated in FIGS. 1, 2 and 3 as being approximately 90 degrees (i.e., a “right” angle). In the alternate embodiments described hereinbelow, the angle is described as being less than or greater than 90 degrees.

[0053]FIG. 5 illustrates a portion of an alternate embodiment of a clasp, wherein the tab 154′ extends at an acute angle (less than 90 degrees), such as approximately 80 degrees, from the body portion 152′ of the spring element 150′. The notch 140′ in the shaft element 130′ is shaped accordingly so that the tab 154′ can enter the notch 140′. This is one way of providing for better holding power and greater strength (“strong hold”).

[0054]FIG. 6 illustrates portion of an alternate embodiment of a clasp, wherein the tab 154″ extends at an obtuse angle (greater than 90 degrees), such as approximately 100 degrees, from the body portion 152″ of the spring element 150″. The notch 140″ in the shaft element 130″ is shaped accordingly so that the tab 154″ can enter the notch 140″. This is one way of providing for a non-destructive release mechanism to guard against too much applied force and, therefore, to protect the integrity of the cord 102/104. In other words, if excess tension is applied to clasp, it will disengage, without first requiring that the shaft member be rotated (“safety release”).

[0055]FIG. 7 illustrates an alternate embodiment of the invention wherein at least two spring elements are provided. In this example, three spring elements 150 a, 150 b and 150 c are provided, each disposed on an external surface of the latch element 110A, and affixed thereto such with affixing means such as a rivet 156 a, 156 b and 156 c, respectively. The spring elements 150 a, 150 b and 150 c have an elongate body portion 152 a, 152 b, 152 c, respectively, and a tab 154 a, 154 b and 154 c extending through a corresponding hole (compare 122) in the wall 120A of the latch element 110A. The three spring elements 150 a, 150 b and 150 c are suitably disposed at equal intervals (e.g., 120 degrees) about the circumference of the latch element 110A, as illustrated. The three tabs 154 a, 154 b and 154 c can all be at the same longitudinal position (e.g., distance from the front end) of the latch element 110A, or they can be at different distances from the front end of the latch element 110A.

[0056] The shaft element 130A has three notches 140 a, 140 b and 140 c. The notches 140 a, 140 b and 140 c are located so as to receive a corresponding one of the three tabs 154 a, 154 b and 154 c, respectively. If the tabs are at different distances from the front end of the latch element 110A, the notches would be at corresponding different distances from the front end of the shaft element 130A.

[0057]FIG. 7 shows the clasp engaged. To disengage the clasp, the shaft element 130A would be rotated (e.g., 60 degrees) with respect to the latch element 110A, urging the tabs 154 a, 154 b and 154 c out of the respective notches 140 a, 140 b and 140 c, then pulling the shaft member 130A out of the latch member 110A.

[0058]FIG. 8 illustrates an alternate embodiment of the latch member 810, (compare the latch member 110 of FIG. 1). The latch member 810 is elongate and is generally cylindrical (tubular), having a front end 812, a rear end 814 which is opposite the front end 812, an inside surface 816, and an outside surface 818. The latch member 810 is open at the front end 812 and, in this example, is closed at the rear end 814. The latch member 810 has an inside diameter D1, and its inside surface 816 is preferably of uniform diameter, rather than tapered. The outside surface 818 is shown as being of uniform diameter, but it need not be. The latch member 810 has a cylindrical wall 820. Here, it is shown that the rear end 814 is closed with a plug 815, but the plug could be integral with (a part of) the wall 820.

[0059] In this example, there is no separate spring member 150 with a hook (tab) portion 154. Rather, the wall 820 of the latch member 810 itself forms a spring member 850 having a body portion 852 and a hook (tab) portion 854. The spring member 850 is formed integrally with the latch member 810. The body portion 852 would have a width (circumferential extent) comparable to that of the body portion 152. The tab portion 854 is formed like the previously-described tab portion 154, and extends resiliently into the interior of the latch member 810 to engage a corresponding notch in the pin member 130 (such as has been shown with respect to FIG. 3).

[0060] While the invention has been described in combination with embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing teachings. Accordingly, the invention is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and scope of the appended claims. 

What is claimed is:
 1. A clasp, comprising: an elongate, generally cylindrical, latch member having a front end, a rear end opposite the front end, a wall, an inside surface, an outside surface, and an inside diameter; an elongate, generally cylindrical, shaft member having a front end, a rear end opposite the front end, a length, a notch extending a distance into an external surface thereof, and an outside diameter; and a spring member, disposed on the outside surface of the latch member, and having a tab extending a distance, into the bore of the latch member, for resiliently engaging the notch of the shaft member.
 2. Clasp, according to claim 1, wherein: the outside diameter of the shaft member is less than the inside diameter of the latch member.
 3. Clasp, according to claim 1, further comprising: a hole extending through the wall of the latch member, from the outside surface to the inside surface thereof; wherein the tab extends through the hole.
 4. Clasp, according to claim 3, wherein: the hole is disposed at a position which is approximately 25-50% of a distance from the front end to the rear end of the latch member.
 5. Clasp, according to claim 1, wherein: the inside surface of the latch member has a uniform diameter from the front end to the rear end.
 6. Clasp, according to claim 1, wherein: the latch member is constructed as a thin-walled, strong, round tube, of metal.
 7. Clasp, according to claim 1, further comprising: a hole extending through the wall of the latch member, from the outside surface to the inside surface thereof, at a location closely adjacent the rear end; and a ring disposed in the hole, for attaching to an end of an elongate element.
 8. Clasp, according to claim 1, further comprising: an eyelet in the rear end of the shaft member; and a ring disposed in the eyelet, for attaching to an end of an elongate element.
 9. Clasp, according to claim 1, wherein: the rear end of the latch member is open.
 10. Clasp, according to claim 1, wherein: the shaft member is tapered, from the front end towards the rear end so that it can easily be inserted into the latch member.
 11. Clasp, according to claim 1, wherein: the notch extends radially into the shaft member a distance which is approximately one-third to one-half of the shaft diameter.
 12. Clasp, according to claim 1, wherein: the notch extends circumferentially, approximately 180-degrees around the shaft member, has a front wall, a back wall, and a ramp surface.
 13. Clasp, according to claim 1, wherein: the spring member is elongate and is made of a resilient material.
 14. Clasp, according to claim 1, wherein: the spring member comprises an elongate body portion having a one end which is affixed to the latch member and another opposite end which is a free end; and the tab extends from the free end of the body portion.
 15. Clasp, according to claim 14, wherein: the tab is integrally formed with the body portion.
 16. Clasp, according to claim 1, wherein: the distance that the tab extends into the bore of the latch member is less than half the inside diameter of the latch member.
 17. Clasp, according to claim 1, wherein: the distance that the tab extends into the bore of the latch member is less than the depth of the notch.
 18. Clasp, according to claim 1, wherein: the spring member is formed integrally with the latch member.
 19. Method of engaging a clasp comprising a shaft member insertable into a latch member, comprising: aligning a notch on the shaft member with a tab extending into a bore of the latch member, and inserting the front end of the shaft member into the front end of the latch member; causing the tab to deflect resiliently out of the bore; continuing to insert the shaft member into the latch member until the notch is aligned under the tab, and the tab enters the notch.
 20. Method, according to claim 19, further comprising disengaging the clasp by: rotating the shaft member to a position where the tab is no longer in the notch; and withdrawing the shaft member from the latch member. 